1. Field
The exemplary embodiments disclosed herein relate to a camera, and more particularly, to a light-field camera having a micro-lens array.
2. Description of the Related Art
In a method of taking a plurality of parallax images by using a single camera, a lens array is disposed between an image sensor and an imaging lens of the camera to store a light-field. According to this method, after storing information about an optical direction of a 2D type, an image focus may be re-controlled via post processing. Also, depth information of the pictured image may be extracted by calculating 3D information in the post processing.
Generally, as a distance of light from an optical axis of a lens increases, an effective focal length of the light is reduced. Accordingly, an image of an object is not formed on a flat plane, but instead is formed on a curved surface that is referred to as a Petzval surface.
In the case of a light-field camera of the related art, a light-field image is obtained by positioning a flat lens array in front of a flat image sensor. Accordingly, an image of light that is far away from an optical axis of the light-field camera is far away from a focus position, that is, the flat image sensor, and thus, noise is increased and optical efficiency is also reduced.
A light-field camera can be used to obtain directional optical information of an object by fixing a distance between a lens array and an image sensor, that is, a distance corresponding to a focal length of a lens array, but image resolution may be reduced. In order to solve this problem, a method has been disclosed, whereby an angle resolution is reduced but an image resolution is increased by making a distance between a lens array and an image sensor longer (a real image) or shorter (a virtual image) than a focal length. However, when this method is used, an image formed by a main lens is stored in an image sensor via a lens array. Thus, a viewing angle of a 3-dimensional image with respect to an object may be limited and narrowed.